A sleeve carton typically comprises a rectangular tube with four sides, open at one end and sometimes at both ends. A sleeve carton may serve as a shipping, display or dispensing unit for other packages, such as blister packs. Flat display packages commonly called blister packs are used to hold a conveniently small number of items, such as small light bulbs, on a flat card. The card may include a hole so a group of the flat packages may be strung on a horizontal rod for display and then selection by a consumer. Alternatively, the flat packages may be stored on a shelf in a surrounding sleeve carton to keep the flat packages from disordering. The sleeve carton filled with flat packages may also be sold as a unit.
The sleeve carton holding flat packages poses a number of problems. The flat packages must be loaded in the sleeve carton, and securely retained during shipping and display. The blister side of a blister pack is frequently irregular, so loading the sleeve carton by hand is often preferred. One method of forming the sleeve carton would be to stack a series of flat packages and wrap a cover around the stack leaving two ends open for access. Unfortunately, for soft flat packages, a wrapped sleeve carton is difficult to form since the retained flat packages may be crushed. The soft flat packages also tend to fall from the open ends. An alternative, is to form a solid sleeve carton and insert the flat packages. The inserted flat packages may be dislodged where only friction holds the flat packages in the sleeve carton. A further alternative is to partially enclose the sleeve carton with a sealed flap or other standard closure. The inserted flat packages may subsequently be exposed by removing the sealed flap to open the sleeve carton. Enclosing requires additional expense, and subsequent opening invites tearing of the sleeve carton. Hand loading is likely to be frustrated by the flaps, covers, or other known features needed for retaining loosely included packages. There is then a need to provide a sleeve carton that securely holds the enclosed flat packages, and is easily loaded by hand or machine.
Similarly, the retained flat packages must also be easily removed by a customer, without having to damage the sleeve carton, or letting the remaining flat packages spill out. For simple wrapped sleeve carton, the first flat package is likely to be difficult to remove, but remaining flat packages may fall out freely since the compression induced friction holding the flat packages has been reduced. Sleeve cartons that require opening need attention by clerks to see that each sleeve carton is opened correctly, and not misopened by unconcerned consumers. There is then a need to provide a durable sleeve carton that is easily accessed by a user.